This article is the result of two different researches about the roles of French teachers in the secondary school and the use of ICT in their class practice. The first research was conducted in the laboratory ''EDA'' (Education et Apprentissages) in the University Paris 5 and concerned the French physics teachers. The second research was conducted in the French Pedagogical Institute, ''INRP'' (Institut National de la Researche Pedagogie) and concerned the teachers of biology. Teaching and learning physics and biology have always been difficult. New teaching strategies have emerged with the introduction in 2000 of the Personal Guided Projects (TPEs, ''Travaux Personnels Encadres in French) and teachers themselves need the opportunity to develop new classroom skills and new models of teaching. The TPEs represent in France a new step in the organisation of the school activity. In this new form of learning, two to four students organise a project in common, which concerns at least two disciplines. The students in the TPE have to define a topic of survey and develop a problematic. This topic must lead to a production of a dissertation. Access to the information is crucial to the success of TPEs. In this context, it seems convenient to base the TPEs on ICT as a research tool. Based on individual interviews and their content analysis this research elicits the new roles and the new attitudes of teachers in the context of new technologies. The integration of ICT requires the acceptance of the teachers. They adopt innovations when they fit with their teaching methods and which allow them to control the class and the students' activities. In this context, our purpose is to provide comparative information for the potential impact of ICT for the French teachers of physics and biology. New models of teaching seem to be constructed by teachers who feel more active and more dynamic when using new class practices to teach physics and biology. These teachers are aware of the fact that new teachers' roles are developing. The interviewed teachers express great satisfaction when they teach with ICT because it creates greater class autonomy. However, in spite of their general enthusiasm, the teachers also reported that they had encountered technical problems in the use of ICT in class and particularly with the Internet. New teaching strategies have emerged with the introduction of the ICT and teachers themselves need the opportunity to develop new classroom skills and new models of teaching. Both physics and biology teachers in France present ICT by evoking mainly Internet as a type of continuing teacher training: they have developed a new image of their job, a new relation to knowledge and a new way of teaching with less teachers' interventions.